<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>百分比布局</title>
</head>
<style>
  div{
    display:-webkit-flex;
    display: flex;
  }

  article,aside{
    border:1px solid red;
  }
  /* u-1of2 元素占50% 其余自适应*/
  .Grid-cell.u-1of2 {
    flex: 0 0 50%;
  }

  /* 直接一行内扩充************************/
  .Grid-cell {
    flex: 1;
  }

  .Grid-cell.u-full {
    flex: 0 0 100%;
  }

  /* u-1of4 占25%其余自适应 */
  .Grid-cell.u-1of4 {
    flex: 0 0 25%;
  }

  .Grid-cell.u-1of3 {
    flex: 0 0 33.3333%;
  }
</style>
<body>
  <h3>百分比布局: 某个网格的宽度为固定的百分比，其余网格平均分配剩余的空间</h3>
  <div>
    <article class="Grid-cell u-1of2 ">1/2</article>
    <aside class="Grid-cell">auto</aside>
    <aside class="Grid-cell">auto</aside>
  </div>

  <div>
    <articla class="Grid-cell" >auto</article>
    <aside class="Grid-cell u-1of3" >u-1of3</aside>
  </div>

  <div>
    <aside class="Grid-cell u-1of4" >1/4</aside>
    <article class="Grid-cell" >auto</article>
    <aside class="Grid-cell u-1of3" >1/3</aside>
  </div> 
</body>
</html>

